NOTES
1136
Vol. 60
NOTES FREEZING POINT DIAGRAMS O F SOME SYSTEMS CONTAINING TNT. I1
samples were taken and temperatures were determined with 10% rhodium-platinum thermocouples. Supercooling of the melts was minimized by withBY LOHRA. BURKARDT AND DONALD W. MOORE drawing small portions of the melt on a platinum Chemistry Division, U. S. Naval Ordnance Test Station, China Lake, ribbon, allowing the material t o solidify and reCalifornia turning it to the melt. Received September 6 , 1966 The system TNT-2,4,6-trinitro-1,3-dimethyl-54I n the course of a study of the physical properties butylbenzene was found t o form two compounds. of 2,4,6-trinitrotoluene (TNT), data are being ac- The first compound contains one mole of 2,4,6quired on a number of binary systems containing trinitro-l,3-dimethyl-5-t-butylbenzeneand three TNT. Freezing point data of two of these sys- moles of TNT. This compound melts a t 71.5'. tems TNT-2,4,6-trinitro-l,3-dimethyl-5-t-butylben-The second compound, which appears to contain zene and TNT-2,4,6-trinitrobenzoic acid are pre- two moles of 2,4,6-trinitro-l,3-dimethyl-5-t-butylsented here. These systems do not appear t o have benzene, is indicated by the incongruent melting been investigated previously. point of 83.8" found a t a composition of 61.5 mole The T N T used in these studies had a vacuum % 2,4,6-trinitro-1,3-dimethyl-5-t-butylbenzene. melting point of 80.9". The 2,4,6-trinitro-1,3- Two eutectic mixtures are formed. These occur at dimethyl-5-t-butylbenzene was Eastman Kodak 23 and 28 mole % 2,4,6-trinitro-l ,3-dimethyl-5-tGo. material melting a t 111.5'. The trinitroben- butylbenzene and melt a t 70 and 69.5", respeczoic acid was Eastman Kodak Co. material melt- tively. Data for this system are shown in Fig. 1. ing a t 227". The system TNT-2,4,6-trinitrobenzoic acid The apparatus used for determining freezing shows a eutectic mixture melting at 76" and conpoints has been described elsewhere.' Three-gram taining 7.5 mole % 2,4,6-trinitrobenzoic acid. Compositions containing more than 20 mole yo of 2,4,6-trinitrobenzoic acid show evidence of decomposition. Attempts to rerun these compositions resulted in successively lower freezing points with each remelting of the material. Data for this system are shown in Fig. 2.
#
1
THE HEAT OF COMBUSTION OF TRI-sec-BUTYLBORANE BYE. A. HASELEY, A. B. GARRETTAND HARRY H. SISLER~ 0 10 20 30 40 50 GO 70 80 90 100 Mole % 2,4,6-trinitro-1,3-dimethyl-5-t-butylbenzene. Fig. 1.
Contribution from the McPheraon Chemical Laboratory of The Ohio State University, Columbus, Ohio Received April 8, 1066
I n conjunction with work in progress in this Laboratory the heat of combustion of tri-secbutylborane has been determined. It was interesting t o compare the data obtained for this compound with data obtained in a similar study of tri-n-butylborane by Tannenbaum and Schaeffer. la
180
Experimental
160
Tri-sec-butylborane.-Tri-sec-butylborane was prepared according to the method of Johnson, Snyder and Van Campen.* The reaction mixture was fractionated and the fraction boiling between 85 and 86' at 9-10 mm. waa used in this work. The infrared spectrum of the product was in excellent agreement with a spectrum of tri-sec-butylborane supplied by BeachelL8 Apparatus and Procedure.-The combustion measurements were carried out in a non-adiabatic Parr Calorimeter usin a double valve bomb with a capacity of 360 ml. The bomt was calibrated with standard benzoic acid supplied by the Parr Instrument Company, according to the proce-
9 140 120 100
80 0
(1) L. A.
20 30 40 50 60 70 80 90 100 Mole % trinitrobenzoic acid. Fig. 2. Burkardt, D. W. Moore and W. S. McEwan, Reu. Sei. Inat., 10
40. 461-2 (1953).
(1) 8. Tannenbaum and P. S. Schaeffer, J . A m . Chem. SOC.,77, 1385 (1955). (la) Department of Chemistry, Univ. of Florida, Gainesville, Fla. (2) J. R. Johnson, H. R. Snyder and M. G. Van Carnpen, Jr., ibid., 60, 115 (1938). (3) H. C. Beachell, private communication.
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